Light-sensitive vesicular recording materials

ABSTRACT

light-sensitive vesicular imaging materials, suitable for the production of labels, etc., comprise a light-sensitive vesicular imaging layer applied to one surface of a self-supporting plastics sheet or film preferably a polyester film, e.g., an oriented and heat-set film of polyethylene terephthalate, said light-sensitive vesicular imaging layer comprising a polymeric vehicle having uniformly dispersed therein a sensitizing agent which releases a vesicle-forming gas upon exposure to light and may comprise a nitrogent-liberating diazonium salt, said polymeric vehicle comprising a thermoplastic polymer having a nitrogent permeability constant (as defined in the specification) in the range 1 × 10 -15  to 1 × 10 -10  and being softenable upon heating above ambient temperature to permit the gas released by the sensitizing agent in the light-struck areas to form light-scattering or reflecting vesicles therein, e.g., a vinylidenechloride copolymer, and at least one light-reflecting metal layer such that an image formed in the light-sensitive vesicular imaging layer is viewed by means of light reflected by the metal layer, e.g., aluminum. The metal is preferably applied as a single layer on the opposite side of the sheet or film from the imaging layer. A dye may be included in the imaging layer and a self- or pressure-sensitive adhesive layer may be applied to the assembly.



